Grouping Data with Count Note: This starts with the 1.10.1 version of the mongo driver; https://www.nuget.org/packages/mongocsharpdriver/1.10.1 the v2 driver wraps the Async methods to syncronous to stay 'compatible' and as such is slower. So running 'synchronous' using v2 would be disadvantaged by the new driver while async with the async driver may have a minor benefit. The async is covered further down using Driver 2.1.…